<?php

var_dump($nghihoc);

?>
<div id="showchart">
<div id="chart_div" style="width: 800px; height: 400px;"></div>
</div>
 <script type="text/javascript">
      google.load("visualization", "1", {packages:["corechart"]});
      google.setOnLoadCallback(drawChart);
      function drawChart() {
        var data = google.visualization.arrayToDataTable([
          ['Năm', 'học kỳ 1', 'học kỳ 2'],
          ['<?php echo date('Y')-5 ?>',  1000,      400],
          ['<?php echo date('Y')-4 ?>',  1170,      460],
          ['<?php echo date('Y')-3 ?>',  660,       1120],
          ['<?php echo date('Y')-2 ?>',  1030,      540],
          ['<?php echo date('Y')-1 ?>',  1030,      540],
          ['<?php echo date('Y') ?>',  1030,      540]
        ]);

        var options = {
          title: 'Company Performance'
        };

        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        chart.draw(data, options);
      }
    </script